Lead-184

Properties and data of the isotope ¹⁸⁴Pb.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

See also: List of individual Lead isotopes (and general data sources).

General data

Name of the isotope:Lead-184; Pb-184Symbol:¹⁸⁴Pb or 18482PbMass number A:184 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:102Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.2439024390244 (= neutron-proton ratio)Neutron excess (N-Z):20Isotopic mass:183.988136(14) u (atomic weight of Lead-184)Nuclide mass:183.9431576 u (calculated nuclear mass without electrons)Mass excess:-11.05124 MeVMass defect:1.537338056 u (per nucleus)Nuclear binding energy:1432.02117514 MeV (per nucleus)
7.78272378 MeV (average binding energy per nucleon)Separation energy:S_N = 11.55(3) MeV (first neutron)
S_P = 1.753(16) MeV (first proton)Half-life:490(25) msDecay constant λ:1.4145860827754 s^-1Specific activity α:4.655101993977 × 10⁺²¹ Bq g^-1
125813567404.81 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.3930(28) femtometer fmYear of discovery:1980

Radioactive Decay

Half-life T_½ = 490(25) ms respectively 4.90 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸⁰Hg	80(15) %	6.774(3) MeV
β⁺	¹⁸⁴Tl	20(15) %	5.832(16) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁸⁴Bi, ¹⁸⁸Po.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 102) and isobaric (same nucleon number A = 184) with Lead-184. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 102	Isobar A = 184
60	¹⁶²Nd
61	¹⁶³Pm
62	¹⁶⁴Sm
63	¹⁶⁵Eu
64	¹⁶⁶Gd
65	¹⁶⁷Tb
66	¹⁶⁸Dy
67	¹⁶⁹Ho
68	¹⁷⁰Er
69	¹⁷¹Tm
70	¹⁷²Yb	¹⁸⁴Yb
71	¹⁷³Lu	¹⁸⁴Lu
72	¹⁷⁴Hf	¹⁸⁴Hf
73	¹⁷⁵Ta	¹⁸⁴Ta
74	¹⁷⁶W	¹⁸⁴W
75	¹⁷⁷Re	¹⁸⁴Re
76	¹⁷⁸Os	¹⁸⁴Os
77	¹⁷⁹Ir	¹⁸⁴Ir
78	¹⁸⁰Pt	¹⁸⁴Pt
79	¹⁸¹Au	¹⁸⁴Au
80	¹⁸²Hg	¹⁸⁴Hg
81	¹⁸³Tl	¹⁸⁴Tl
82	¹⁸⁴Pb	¹⁸⁴Pb
83	¹⁸⁵Bi	¹⁸⁴Bi
84	¹⁸⁶Po